UNITED NATIONS (BNO NEWS) -- The United Nations human rights office on Friday urged the Pakistani government to investigate a series of killings and disappearances of journalists in the country, particularly in Balochistan province.

In the past week alone, there have been several reports of human rights violations against journalists, human rights defenders and political activists in the western province of Balochistan.

On Monday, the bodies of four missing activists of the Baloch Students Organization (BSO) were found in Mastung, about 50 kilometers (31 miles) south of the Balochistan capital of Quetta, the Express Tribune reported on Friday.

Meanwhile, the Office of the UN High Commissioner for Human Rights (OHCHR) received reports about the killing of a journalist, Munir Shakir, in Khuzdar of Balochistan on August 14, and the disappearance of another journalist, Rehmatullah Darpakhel, in North Waziristan on August 11.

"We are very concerned that such incidents are not abating in Pakistan," OHCHR spokesman Rupert Colville said. "We call on all responsible parties to immediately stop such violations of human rights, and we urge the Government to take immediate steps to independently investigate these cases."

Colville noted that Pakistan is cited by various journalist groups as one of the most dangerous places for media professionals, with at least 16 journalists killed in 2010 alone. According to the Committee to Protect Journalists (CPJ), nine journalists have been killed in Pakistan so far this year.

"None of the cases have been investigated to the full," Colville told reporters in Geneva. In that matter, the CPJ further stated that Pakistan has a near-perfect record of impunity in journalist murders, with 17 unsolved cases since 2001.

Colville added that in Balochistan alone, there were reports that 25 people, including journalists, writers, students and human rights defenders, have been subject to extrajudicial killings in the first four months of 2011.

Most notably this year, the Pakistan Bureau Chief of Asia Times Online, Syed Saleem Shahzad, was found dead in northeast Pakistan in late May. Human rights organizations and the U.S. government have accused Pakistan's Inter-Services Intelligence (ISI) agency of carrying out the murder, although the Pakistani government rejected those accusations.

A report issued in June by Pakistan's human rights commission revealed that 143 people, including journalists, were reported missing in Balochistan as of May this year. The Voice for Baloch Missing Persons (VFBMP) organization has said that around 190 Baloch activists have been found dead during the past 13 months.